Goose astrovirus (GAstV) leads to viscera and joints urate deposition in 1- to 20-day-old goslings, with a mortality rate of up to 50%, posing a severe threat to entire colonies; however, there is no efficient prevention and control method for GAstV infection. This study describes a prophylactic anti-GAstV strategy based on the specific immunoglobulin Y (IgY) from egg yolk. The specific IgY was produced by 22-week-old laying hens intramuscularly immunized with the inactivated GAstV three consecutive times, with 2-week intervals. The egg yolk was collected weekly after the immunization and the anti-GAstV IgY titer was monitored using an agar gel immune diffusion assay (AGID). The results revealed that the AGID titer began to increase on day 7, reached a peak on day 49, and remained at a high level until day 77 after the first immunization. The specific IgY was prepared from the combinations of egg yolk from day 49 to day 77 through PEG-6000 precipitation. Animal experiments were conducted to evaluate the effects of prevention and treatment. The result of the minimum prophylactic dose of the IgY showed that the protection rate was 90.9% when 2.5 mg was administrated. Results of the prevention and the treatment experiments showed prevention and cure rates of over 80% when yolk antibody was administered in the early stages of the GAstV infection. These results suggested that the specific IgY obtained from immunized hens with the inactivated GAstV could be a novel strategy for preventing and treating GAstV infection.
Necrotic enteritis (NE) is an infectious intestinal disease caused by Clostridium perfringens (C. perfringens) that is now re-emerging and causing concern within the poultry industry. Previously, the supplementation of antibiotics in feed was the most popular control strategy against C. perfringens. However, with the ban on supplementing growth-promoting antibiotics in livestock feed, alternatives to antibiotics will be essential in order to control necrotic enteritis. A possible alternative to antibiotics could be the medium or long chain fatty acids (MCFA or LCFA) as these are able to destroy cell membranes which in turn results in the death of bacteria. In this study, the in vitro antimicrobial activity of different combinations with microencapsulated caprylic acid (C8: 0), capric acid (C10: 0), lauric acid (C12: 0) and myristic acid (C14: 0) against C. perfringens and in vivo control the NE-inducing C. perfringens in broiler chicken were analyzed. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) assay results revealed that three different combinations of medium/long chain fatty acids varied in antimicrobial activities against C. perfringens type A strain (CVCC52, quality control), C. perfringens type A strain (C8-1), C. perfringens type G strain (D25) and C. perfringens type G strain (MZ1). Specifically, combination of C12: 0 and C14: 0 (C12-14) showed the highest antimicrobial activity against the four strains of C. perfringens (MIC ≤ 12.5 μg/mL, MBC = 50 μg/mL), followed by the combination of C10: 0 and C12: 0 (C10-12) (MIC, MBC ≤ 50 μg/mL). The in vivo study, 189 of 818-crossbred chickens that were fed a wheat-based diet and randomly divided into nine groups, with six treatment groups supplemented with either a high dose (1 g/kg) or low dose (0.5 g/kg) of three combinations respectively. The remaining three groups comsisted of a positive group supplement with avilamycin (0.01 g/kg), an infected control and an uninfected control. All chickens were challenged with C. perfringens from day 14 to day 17, except those in the uninfected control group. On day 20, the duodenum and jejunum necrotic lesions scores were calculated and the results showed that there was significant decrease in the C12-C14 high dose group (1.43 ± 0.23, 0.48 ± 0.13) and the C10-12 high dose group (1.52 ± 0.19, 0.48 ± 0.11) compared to the infected group (2.86 ± 0.21, 1.20 ± 0.28). This finding indicated that dietary microencapsulated C12-C14 and C10-C12 could inhibit the growth of C. perfringens in chickens, which proves is viability to serve as an alternative to antibiotics used for necrotic enteritis caused by C. perfringens.
Five hundred and six fresh fecal samples were collected from Lu'an, Fuyang, Suzhou, Chizhou, Wuhu, Chuzhou and Bozhou in Anhui Province, and detected firstly by direct smear microscopy. The microscopy-positive samples were amplified by nested PCR targeting the triosephosphate isomerase (TPI) and glutamate dehydrogenase(GDH) genes. The positive PCR products were sequenced in both directions. The sequences were analyzed by ClustalX 1.81 for sequence alignment and the neighbor-joining trees were constructed by Mega 5.05. Thirty-two out of 506 fecal specimens were diagnosed as Giardia-positive by microscopy with an infection rate of 6.3%. 23 and 16 of the samples were typed as assemblage E by the TPI (530 bp) and GDH (450 bp) genes, respectively. These findings indicated that there was a different distribution of subtypes of assemblage E in different areas. The zoonosis genotypes such as assemblage A or B was not found in the present study.
Introduction Enterotoxic Escherichia coli (ETEC) is the main pathogen that causes diarrhea, especially in young children. This disease can lead to substantial morbidity and mortality and is a major global health concern. Managing ETEC infections is challenging owing to the increasing prevalence of antibiotic resistance. Berberine, categorized as a substance with similarities in “medicine and food,” has been used in China for hundreds of years to treat gastrointestinal disorders and bacteria-induced diarrhea. This study investigated the preventive effect of dietary berberine on the intestinal mucosal barrier induced by ETEC and the microbial community within the intestines of weaned piglets. Methods Twenty-four piglets were randomly divided into four groups. Piglets were administered either a standard diet or a standard diet supplemented with berberine at concentrations of 0.05 and 0.1%. and orally administered ETEC or saline. Results Dietary supplementation with berberine reduced diamine oxidase, d-lactate, and endotoxin levels in piglets infected with ETEC ( P < 0.05). Berberine increased jejunal villus height, villus/crypt ratio, mucosal thickness ( P < 0.05), and goblet cell numbers in the villi and crypts ( P < 0.05). Furthermore, berberine increased the optical density of mucin 2 and the mucin 2, P-glycoprotein, and CYP3A4 mRNA expression levels ( P < 0.05). Berberine increased the expressions of zonula occludins-1 (ZO-1), zonula occludins-2 (ZO-2), Claudin-1, Occludin, and E-cadherin in the ileum ( P < 0.05). Moreover, berberine increased the expression of BCL2, reduced intestinal epithelial cell apoptosis ( P < 0.05) and decreased the expression of BAX and BAK in the duodenum and jejunum, as well as that of CASP3 and CASP9 in the duodenum and ileum ( P < 0.05). Berberine decreased the expression of IL-1β, IL-6, IL-8, TNF-α, and IFN-γ ( P < 0.05) and elevated total volatile fatty acids, acetic acid, propionic acid, valeric acid, and isovaleric acid concentrations ( P < 0.05). Notably, berberine enhanced the abundance of beneficial bacteria including Enterococcus, Holdemanella, Weissella, Pediococcus, Muribaculum, Colidextribacter, Agathobacter, Roseburia, Clostridium, Fusicatenibacter , and Bifidobacterium . Simultaneously, the relative abundance of harmful and pathogenic bacteria, such as Prevotella, Paraprevotella, Corynebacterium, Catenisphaera, Streptococcus, Enterobacter , and Collinsella , decreased ( P < 0.05). Discussion Berberine alleviated ETEC-induced intestinal mucosal barrier damage in weaned piglets models. This is associated with enhancement of the physical, chemical, and immune barrier functions of piglets by enhancing intestinal microbiota homeostasis.
Six healthy no fascioliasis goats confirmed by fecal examination and Dot-ELISA were chosen and randomly divided into Ⅰ,Ⅱ,Ⅲ groups.Each goat of Ⅰ,Ⅱ groups was orally dosed once 200 and 500 Fasciola hepatica metacercariae and during 11 weeks after infection used for the experiment study.Blood sample was collected by jugular vein weekly,to determine IL-2 and TNF-α levels in serum and IL-2 in supernatant with proliferation of PBL of goats infected with Fasciola hepatica.The results showed that IL level in serum of Ⅰ group goats decreased,whereas that of Ⅱ group goats increased,TNF-α levels in serum and IL-2 in supernatant with proliferation of PBL of goats increased after infection.PBL of goats was responsible for antigen 1 week after infection.Immune response of PBL of goats infected with Fasciola hepatica on the special and non-special antigen obviously increased.The results suggested that TNFα would participate in the course of liver damage caused by Fasciola hepatica.There was significant effect of the dose of Fasciola hepatica metacercariae on IL-2 level in serum,and that IL-2 have an important role in defense system of host.
Abstract Background: Swine acute diarrhea syndrome coronavirus (SADS-CoV) causes acute vomiting and diarrhea of piglets, leading to significant financial losses in pig industry. Recombinase polymerase amplification (RPA) technology is the second method for nucleic acid amplification under constant temperature conditions besides loop-mediated isothermal amplification (LAMP). The study established a real-time reverse transcription (RT)-RPA assay for early confirmatory diagnoses to detection SADS-CoV. Results: The detection limit of the real-time RT-RPA was 74 copies/µL of SADS-CoV genomic RNA standard in 95% of cases. The assay was performed in less than 30 min and no cross-reactions were observed with 8 other common viruses that affect swine, namely, CSFV, PRRSV, PRV, SIV, SVA, TGEV, PEDV, or PDCoV. The coefficient of variation (C.V.) values of the two standards dilutions and a positive clinical sample ranged from 0 to 4.5%. A total of 72 clinical fecal samples from swine with diarrheal symptoms were analyzed via the developed RT-RPA and qRT-PCR. There was 98.61% agreement between the RT-RPA and the qRT-PCR results. Conclusions: These results indicate that the developed RT-RPA assay has good specificity, sensitivity, stability, and repeatability. In summary, the established RT-RPA assay could satisfy the demand for infield diagnoses, and is suitable for use in remote areas as it is fast, portable, and cost-effective.
To investigate the prevalence of Neospora caninum infection in the intestine of pet dogs in areas of Anhui and Zhejiang.A total of 315 fecal samples from pet dogs were collected in pet clinics from April to December 2013 in Baohe District in Hefei city, Xuanzhou District in Xuancheng city, Fengyang County in Chuzhou city, Longzihu District in Bengbu city, and Si County in Suzhou City in Anhui Province, as well as in Yuhang District in Hangzhou city of Zhejiang province. All samples underwent nested-PCR targeting Neospora-specific gene NCLI-004830. The results were further confirmed by PCR amplification of N. caninum ITS1 followed by sequence analysis.The rate of N. caninum infection in the 315 samples was 1.59% (5/315). The infection rate in Chuzhou and Bengbu was 3.37% and 6.45%, respectively, and no N. caninum infection was found in the remaining areas. There was no association between the infection rate and the sex or age of the dogs.N. caninum infection is prevalent in pet dogs in Chuzhou and Bengbu of Anhui.
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